Category: DNA & Genetics
DNA Test
Also known as: Genetic test
A DNA test is any test that analyses deoxyribonucleic acid, the molecule carrying genetic information, in order to answer a specific question. Different DNA tests answer very different questions. Relationship tests compare genetic markers between two people, wellness tests look at genetic variations associated with traits such as nutrition or fitness, and clinical genetic tests are ordered by healthcare professionals to investigate inherited conditions. The type of test determines what the result can and cannot tell you, and a consumer wellness DNA test is not a diagnostic test.
What DNA is
DNA, or deoxyribonucleic acid, is the molecule that carries much of the genetic information used in the development and functioning of living organisms. Most cells in the human body contain DNA. Sections of DNA are called genes, and small differences in DNA sequence between people are part of what makes individuals different from one another. WHO describes genomics as the study of the whole of a person's genetic material and how it interacts with health.
The main types of DNA test
"DNA test" is an umbrella phrase, not one product. The main categories answer different questions:
- Relationship testing, such as paternity testing, compares DNA markers between two people to assess whether their genetic profiles are consistent with a biological relationship.
- Wellness and lifestyle testing looks at selected genetic variations associated with traits such as nutrition, fitness, skin and ageing, and presents them as personalised insights.
- Clinical genetic and genomic testing is arranged through a healthcare professional to diagnose or investigate an inherited condition.
- Carrier and predictive testing assesses whether someone carries a genetic change that could be passed on, or is associated with an increased chance of developing a condition.
- Ancestry testing estimates likely geographic origins by comparing DNA against reference populations.
How a DNA sample is collected
Most consumer DNA tests need only a saliva sample or a buccal swab, which is a swab rubbed against the inside of the cheek. Both collect cells that carry DNA, and neither requires a blood draw. The sample is then sent to a laboratory for analysis.
Collection technique matters. Following the instructions supplied with the specific kit helps ensure the laboratory receives enough usable material to analyse.
What a DNA test cannot tell you
This is where the type of test matters most. A consumer wellness DNA test is not intended to diagnose, treat, prevent or determine whether someone has a disease or medical condition. It reports associations that research has found between particular genetic variations and particular traits.
Genetics is also only one input. Having a genetic predisposition does not mean an outcome is certain, because environment, behaviour, age and other biological factors all contribute. Genetic test results can be complex to interpret, and their meaning depends on the specific test performed.
Clinical genetic and genomic testing in a healthcare setting is a different activity, usually arranged with a doctor or genetic counsellor who can interpret the result in the context of your personal and family history.
Direct-to-consumer DNA testing
Tests bought directly by consumers, rather than ordered by a clinician, are known as direct-to-consumer or DTC genetic tests. The Ministry of Health in Singapore has published guidance on direct-to-consumer genetic testing services.
HealthHub advises understanding what a direct-to-consumer test does and does not cover before buying one, and speaking to a healthcare professional if a result raises a health concern.
Reading a DNA test result
Two terms come up repeatedly in results. Your genotype is the genetic variant or combination of variants you carry at a specific location in your DNA. Your phenotype is the characteristic that is actually observed, which may result from genetics together with environment and lifestyle.
A result showing a particular variant is therefore a statement about genetics, not a prediction of an outcome. If a result concerns you, discuss it with an appropriately qualified healthcare professional rather than acting on it alone.
Frequently asked questions
Is a DNA test the same as a genetic test?
The terms are often used interchangeably. In practice "genetic test" is more common in clinical settings, where testing is arranged through a healthcare professional, while "DNA test" is more commonly used for consumer tests such as wellness, ancestry and relationship testing.
Can a DNA test diagnose a disease?
A consumer wellness DNA test cannot. It is not intended to diagnose, treat, prevent or determine whether someone has a disease or medical condition. Clinical genetic testing arranged through a healthcare professional is a separate type of testing and can be used diagnostically.
What sample does a DNA test need?
Most consumer DNA tests use a saliva sample or a cheek swab, both of which collect cells containing DNA. Neither requires a blood sample. Follow the instructions supplied with the kit, because collection quality affects whether the laboratory can analyse the sample.
Does a genetic predisposition mean I will develop that condition?
No. A predisposition means your genetic makeup is associated with an increased or decreased tendency towards a trait or outcome. It is not a certainty. Environmental, behavioural and other biological factors also play important roles.
Do I need a doctor to interpret DNA test results?
For wellness and lifestyle insights, no. For anything that raises a health concern, or for clinical genetic testing, results should be interpreted with an appropriately qualified healthcare professional who can consider your personal and family history.
Related terms
Related Camtech Health tests
References
Understanding your health information
Our glossary is designed to help make health and testing terminology easier to understand.
The information provided here is for general educational purposes only and should not replace professional medical advice, diagnosis or treatment. The purpose and regulatory status of individual Camtech Health tests may differ depending on the product and country in which they are supplied.
If you have symptoms, receive an unexpected result or are concerned about your health, speak with an appropriately qualified healthcare professional.
